Apparatuses and methods involving accessing distributed sub-blocks of memory cells

ABSTRACT

Apparatuses and methods involving accessing distributed sub-blocks of memory cells are described. In one such method, distributed sub-blocks of memory cells in a memory array are enabled to be accessed at the same time. Additional embodiments are described.

PRIORITY APPLICATION

This application is a continuation of U.S. application Ser. No.13/590,926, filed Aug. 21, 2012, which is incorporated herein byreference in its entirety.

BACKGROUND

Semiconductor memory devices formed in integrated circuits (ICs) areused in many electronic devices such as personal digital assistants(PDAs), laptop computers, mobile phones and digital cameras.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are illustrated by way of example and not limitation inthe figures of the accompanying drawings in which:

FIG. 1 is a block diagram of an apparatus in the form of a memory deviceaccording to various embodiments of the invention;

FIG. 2 is a schematic circuit view of an apparatus in the form of adecoder circuit according to various embodiments of the invention;

FIG. 3 is a block diagram of an apparatus in the form of a memory deviceaccording to various embodiments of the invention;

FIG. 4 is a block diagram of the memory device of FIG. 3 according tovarious embodiments of the invention;

FIG. 5 is a cross-sectional view of a semiconductor constructionaccording to various embodiments of the invention;

FIG. 6 is a flow diagram of one method according to various embodimentsof the invention; and

FIG. 7 is a block diagram of an apparatus in the form of a memory deviceaccording to various embodiments of the invention.

DETAILED DESCRIPTION

For the purposes of this document, a memory cell (cell) includes a phasechange memory cell, a dynamic random access memory (DRAM) memory cell,or a charge storage memory cell, such as a transistor having a chargetrap or a floating gate, for example, although embodiments are notspecifically limited to just those cells. Each cell may comprise amulti-state device capable of storing one of multiple separate anddistinct states, each state representing different data. An “apparatus”can refer to any of a number of structures, such as circuitry, a deviceor a system.

Electrical current can flow in a cell during an operation such as aprogramming operation, a read operation or an erase operation on thecell. A substantial amount of current can flow through one region of amemory array if multiple cells are being accessed at the same time andthe cells are near each other in the same region. The cells outside theregion may not be drawing current when the cells in the region are beingaccessed, and an imbalance in current flow can result in noise in thememory array.

The inventor has discovered that the challenges noted above, as well asothers, can be addressed by accessing multiple sub-blocks of cells thatare distributed across a memory array at the same time. The current thatflows through the cells in the sub-blocks during an operation is thendistributed across the memory array.

FIG. 1 is a block diagram of an apparatus in the form of a memory device100 according to various embodiments of the invention. A substantiallyrectangular two-dimensional array 102 of cells and a sense/cache circuit104 are formed on a semiconductor substrate 106. The cells in the array102 are divided into sub-blocks 110, 114, 116, 118, 120, 124, 126, 128,130, 134, 136, 138, 140, 144, 146 and 148. Each of the sub-blocks110-148 includes two or more cells that can be accessed by one or moreaccess lines (e.g., word lines, not shown) and provide data on one ormore data lines (not shown) that are coupled to the sense/cache circuit104. For example, the sub-block 110 includes a cell 149. Each of thesub-blocks 110-148 may contain thousands of cells. A three-dimensionalarray of cells may comprise multiple two-dimensional arrays of cellssuch as the array 102 stacked one over the other.

The illustrated array 102 is divided into four rows of sub-blocks, eachrow of sub-blocks in the array 102 comprising a sub-array including fourof the sub-blocks 110-148. The illustrated array 102 is also dividedinto four columns of the sub-blocks 110-148. Boundaries of thesub-blocks 110-148 are shown by horizontal and vertical lines in FIG. 1.

Each of the sub-blocks 110-148 in the array 102 has a location that canbe defined with reference to a first coordinate and a second coordinatein a coordinate system. For example, each sub-block can be located in atwo-dimensional array with reference to an x-coordinate and ay-coordinate from a reference location (e.g., origin) in the Cartesiancoordinate system. Sub-blocks may be located in the array 102 accordingto other coordinate systems such as the Polar coordinate system. Forexample, a sub-block can be located in the array 102 by a radialcoordinate from a corner of the array 102 and an angular coordinate froma boundary of the array 102.

Each of the sub-blocks 110-148 can have dimensions of, for example,approximately 800 micrometers by approximately 200 nanometers, at leastaccording to one embodiment of the invention. Sub-blocks can be locatedin the array 102 according to the Cartesian coordinate system with anorigin at the lower left corner of the sub-block 110. A horizontalboundary for the sub-blocks 110, 128, 136 and 144 is at an x-coordinate152 that is, for example, approximately 800 micrometers from the origin.The sub-blocks 114, 120, 138 and 146 are between the x-coordinate 152and an x-coordinate 154 that is, for example, approximately 1600micrometers from the origin. The sub-blocks 116, 124, 130 and 148 arebetween the x-coordinate 154 and an x-coordinate 156 that is, forexample, approximately 2400 micrometers from the origin. The sub-blocks118, 126, 134 and 140 are between the x-coordinate 156 and anx-coordinate 158 that is, for example, approximately 3200 micrometersfrom the origin. A vertical boundary for the sub-blocks 110, 120, 130and 140 is at a y-coordinate 162 that is, for example, approximately 200nanometers from the origin. The sub-blocks 114, 124, 134 and 144 arebetween the y-coordinate 162 and a y-coordinate 164 that is, forexample, approximately 400 nanometers from the origin. The sub-blocks116, 126, 136 and 146 are between the y-coordinate 164 and ay-coordinate 166 that is, for example, approximately 600 nanometers fromthe origin. The sub-blocks 118, 128, 138 and 148 are between they-coordinate 166 and a y-coordinate 168 that is, for example,approximately 800 nanometers from the origin.

All cells in a block of cells (where a block comprises a group ofsub-blocks) in the array 102 are enabled to be accessed at the sametime. Cells outside the block are not enabled to be accessed when acell(s) in the block is accessed such as, for example, during aprogramming operation, a read operation or an erase operation. In theillustrated embodiment, each block of cells includes four of thesub-blocks 110-148 that can be enabled by a decoder circuit and aredistributed across the array 102.

FIG. 2 is a schematic circuit view of an apparatus in the form of adecoder circuit 200 according to various embodiments of the invention.The cells in each of the sub-blocks 110-148 can be enabled to beaccessed by a block enable signal provided (e.g., generated) by anenable circuit, such as a logic gate selectively activated in responseto decoding signals, in a decoder circuit such as the decoder circuit200. The decoder circuit 200 can enable the cells of two of thesub-blocks 110-148 in the array 102 to be accessed, and the cells of twoothers of the sub-blocks 110-148 can be enabled to be accessed at thesame time by a substantially similar decoder circuit (not shown). Forexample, the block enable signal can enable access lines coupled to thecells in the sub-blocks to receive programming voltages or read voltagesor erase voltages.

The sub-blocks 118, 128, 138 and 148 comprise a first sub-array in thearray 102, and the cells in each of the sub-blocks 118, 128, 138 and 148can be enabled by a block enable signal from one of four respectivecircuits such as logic gates such as AND gates 202, 204, 206 and 208.Each of the AND gates 202-208 includes a first input coupled to one oftwo lines 212 and 214 carrying complementary decoding signals a0 and a1,respectively. One of the decoding signals a0 and a1 is high, and one ofthe decoding signals a0 and a1 is low. Each of the AND gates 202-208includes a second input coupled to one of two lines 216 and 218 carryingcomplementary decoding signals b0 and b1, respectively. One of thedecoding signals b0 and b1 is high, and one of the decoding signals b0and b1 is low. The inputs of the AND gates 202-208 are coupled to thelines 212-218 in a pattern such that only one of the AND gates 202-208provides a high block enable signal to enable only one of the sub-blocks118, 128, 138 and 148 in the first sub-array at a time. The decodingsignals a0, a1, b0 and b1 are provided to select one of the sub-blocks118, 128, 138 and 148 based on an address in a memory request.

The sub-blocks 116, 126, 136 and 146 comprise a second sub-array in thearray 102, and the cells in each of the sub-blocks 116, 126, 136 and 146can be enabled by a block enable signal from one of four respective ANDgates 232, 234, 236 and 238. Each of the AND gates 232-238 includes afirst input coupled to one of the two lines 212 and 214 carrying thedecoding signals a0 and a1, respectively. Each of the AND gates 232-238includes a second input coupled to one of the two lines 216 and 218carrying the decoding signals b0 and b1, respectively. The inputs of theAND gates 232-238 are coupled to the lines 212-218 in a pattern suchthat only one of the AND gates 232-238 provides a high block enablesignal to enable only one of the sub-blocks 116, 126, 136 and 146 in thesecond sub-array at one time. The decoding signals a0, a1, b0 and b1 canbe changed to disable one or more of the sub-blocks 118, 128, 138, 148,116, 126, 136 and 146 that were enabled and to enable one or more of thesub-blocks 118, 128, 138, 148, 116, 126, 136 and 146 that were notenabled.

With reference to FIG. 1, operation of the decoder circuit 200 canenable the cells in the sub-blocks 110, 114, 116 and 118 to be accessedat the same time while the cells of the sub-blocks 120, 124, 126, 128,130, 134, 136, 138, 140, 144, 146 and 148 are not enabled to be accessedduring a memory operation. Each enabled sub-block 110 has anx-coordinate and a y-coordinate that are not the same as thex-coordinate and the y-coordinate of any of the other enabled sub-blocks114, 116 and 118. For example, the sub-block 110 including the cell 149can have an x-coordinate between 0 and 800 micrometers while thesub-blocks 114, 116 and 118 each have an x-coordinate greater than 800micrometers. The sub-block 110 including the cell 149 can have ay-coordinate between 0 and 200 nanometers while the sub-blocks 114, 116and 118 each have a y-coordinate greater than 200 nanometers.

Each enabled sub-block 110, 114, 116 and 118 is in a row of sub-blocksin the memory device 100 that does not include another enabled sub-blockand is in a column of sub-blocks that does not include another enabledsub-block. Each row of sub-blocks includes only one enabled sub-block ata time and each column of sub-blocks includes only one enabled sub-blockat a time. The enabled sub-blocks 110, 114, 116 and 118 are separatedfrom each other by the sub-blocks 120, 124, 126, 128, 130, 134, 136,138, 140, 144, 146 and 148 that are not enabled to be accessed. Each ofthe enabled sub-blocks 110, 114, 116 and 118 is adjacent only tosub-blocks that are not enabled to be accessed.

FIG. 3 is a block diagram of an apparatus in the form of a memory device300 according to various embodiments of the invention. The memory device300 is three-dimensional and comprises four substantially rectangulartwo-dimensional arrays 302, 304, 306 and 308 of cells that are stackedtogether. The arrays 302, 304, 306 and 308 are shown separated forpurposes of clarity. The memory device 300 also comprises a sense/cachecircuit 310. The arrays 302, 304, 306 and 308 and the sense/cachecircuit 310 are formed on a semiconductor substrate (not shown). In someembodiments, the array 302 may be formed on a substrate, after which thearray 304 is formed over the array 302, after which the array 306 isformed over the array 304, after which the array 308 is formed over thearray 306. In this way, a stack of the arrays 302, 304, 306, 308 isformed over the substrate.

The cells in the arrays 302, 304, 306 and 308 are arranged in sub-blocksof cells. Boundaries of the sub-blocks are shown by horizontal andvertical lines in FIG. 3. Each array 302, 304, 306 and 308 includes fourrows of sub-blocks and 16 columns of sub-blocks for a total of 64sub-blocks of cells in each array 302, 304, 306 and 308. Each of thesub-blocks is located in one row of sub-blocks and in one column ofsub-blocks in one of the arrays 302, 304, 306 and 308. Each row ofsub-blocks in the arrays 302, 304, 306 and 308 comprises a sub-arrayincluding 16 of the sub-blocks. The sub-blocks have substantially thesame dimensions in all of the arrays 302, 304, 306 and 308 such thateach sub-block in each array 302, 304, 306 and 308 is directly underand/or over corresponding sub-blocks in the other arrays 302, 304, 306and 308.

All cells in a block in the arrays 302, 304, 306 and 308 are enabled tobe accessed at the same time. Cells outside the block are not enabled tobe accessed when cells in the block are enabled to be accessed such as,for example, during a programming operation, a read operation or anerase operation. Each block in the memory device 300 includes foursub-blocks in each of the arrays 302, 304, 306 and 308 that can beenabled by a decoder circuit (not shown) and are distributed across thearrays 302, 304, 306 and 308. A block may include sub-blocks having thesame location in the respective arrays 302, 304, 306 and 308. A blockcan include sub-blocks 320, 322, 324 and 326 in the array 302,sub-blocks 340, 342, 344 and 346 in the array 304, sub-blocks 360, 362,364 and 366 in the array 306 and sub-blocks 380, 382, 384 and 386 in thearray 308. The sub-blocks 320, 340, 360 and 380 occupy the same locationin the respective arrays 302, 304, 306 and 308. The sub-blocks 322, 342,362 and 382 occupy the same location in the respective arrays 302, 304,306 and 308. The sub-blocks 324, 344, 364 and 384 occupy the samelocation in the respective arrays 302, 304, 306 and 308. The sub-blocks326, 346, 366 and 386 occupy the same location in the respective arrays302, 304, 306 and 308.

FIG. 4 is a block diagram of the memory device 300 of FIG. 3 accordingto various embodiments of the invention. A block of cells can includesub-blocks 421, 423, 427 and 429 in the array 302, sub-blocks 441, 443,445 and 447 in the array 304, sub-blocks 461, 463, 467 and 469 in thearray 306 and sub-blocks 481, 483, 485 and 487 in the array 308.

The sub-blocks 421, 423, 427 and 429 in the array 302 do not occupy thesame locations as the sub-blocks 441, 443, 445 and 447 in the array 304.The sub-blocks 441, 443, 445 and 447 in the array 304 do not occupy thesame locations as the sub-blocks 461, 463, 467 and 469 in the array 306.The sub-blocks 461, 463, 467 and 469 in the array 306 do not occupy thesame locations as the sub-blocks 481, 483, 485 and 487 in the array 308.Thus, the sub-blocks that form a block can be selected so that thesub-blocks do, or do not occupy the same locations within correspondingarrays in a stack. Many arrangements are possible.

FIG. 5 is a cross-sectional view of a semiconductor construction 500according to various embodiments of the invention. The semiconductorconstruction 500 may comprise a portion of the memory device 100 shownin FIG. 1. The semiconductor construction 500 includes four strings 506of charge storage devices, with each string 506 connected to a separatedata line 510. The strings 506 are coupled to a single common source514. The strings 506 are formed over a p-type silicon substrate 524, andthe potential of the common source 514 is controlled by the operation oftransistors (e.g., complementary metal-oxide semiconductor (CMOS)transistors) in the substrate 524.

An n-type silicon well 530 is formed in the substrate 524. A first p+type diffusion region 534 and a second p+ type diffusion region 538 areformed in the n-type silicon well 530. The first p+ type diffusionregion 534 is coupled to a power supply voltage Vcc node and the secondp+ type diffusion region 538 is coupled to the common source 514. Afirst polysilicon gate 540 is formed over the substrate 524 between thefirst p+ type diffusion region 534 and a second p+ type diffusion region538 to form a p-channel transistor between the power supply voltage Vccnode and the common source 514.

A first n+ type diffusion region 552 and a second n+ type diffusionregion 556 are formed in the substrate 524. The first n+ type diffusionregion 552 is coupled to the common source 514 and the second n+ typediffusion region 556 is coupled to a reference voltage Vss node (e.g.,ground voltage). A second polysilicon gate 560 is formed over thesubstrate 524 between the first n+ type diffusion region 552 and thesecond n+ type diffusion region 556 to form an n-channel transistorbetween the reference voltage Vss node and the data line 514.

The first polysilicon gate 540 and the second polysilicon gate 560 areseparated from the substrate 524 by a dielectric such as silicon dioxide(not shown). Cross-sectional views of the data lines 510 are shown thatare substantially orthogonal to the common source 514. The data lines510 in FIG. 5 are substantially square, but may have a differentgeometry. The CMOS transistors in the substrate 524 can draw currentfrom the common source 514 to the reference voltage Vss node and aredistributed across an array of cells. Operation of the array of cellsaccording to various embodiments of the invention can reduce noise inthe power supply voltage Vcc node and the reference voltage Vss node byoperating as described herein, to more evenly distribute current flowacross the memory device 100.

FIG. 6 is a flow diagram of one method 600 according to variousembodiments of the invention. In block 610, the method 600 starts. Inblock 620, a memory request, perhaps including a command and an address,is received in an apparatus, such as a memory device. In block 630,distributed sub-blocks of memory cells in the apparatus are enabled inresponse to the memory request while other blocks of cells in the memorydevice are not enabled. With reference to FIG. 1 for example, thesub-blocks 110, 114, 116 and 118 might be enabled to be accessed at thesame time while the sub-blocks 120, 124, 126, 128, 130, 134, 136, 138,140, 144, 146 and 148 are not enabled to be accessed. In block 640, thememory request is executed by a controller to program, read or erasecells in the enabled sub-blocks 110, 114, 116 and 118. In block 650, themethod 600 ends. The method 600 more evenly distributes current flowacross the memory device to reduce noise in a power supply voltage nodeand a reference voltage node. Various embodiments may have more or feweractivities than those shown in FIG. 6. In some embodiments, theactivities in FIG. 6 may be repeated, substituted for one another,and/or performed in serial or parallel fashion.

FIG. 7 is a block diagram of an apparatus in the form of a memory device700 according to various embodiments of the invention. The memory device700 is coupled to a control bus 704 to receive multiple control signalsover control signal lines 705. The memory device 700 is also coupled toan address bus 706 to receive address signals A0-Ax on address signallines 707 and to a data bus 708 to transmit and receive data signals.Although depicted as being received on separate physical busses, thedata signals could also be multiplexed and received on the same physicalbus.

The memory device 700 includes one or more arrays 710 of cells that canbe arranged in rows and in columns. The cells of the array 710 cancomprise DRAM cells or phase change cells or charge storage cells (e.g.,Flash memory cells with floating gate transistors or charge traptransistors) according to various embodiments of the invention. Thememory device 700 can comprise a NAND memory device. The array 710 caninclude multiple banks and blocks of cells residing on a single die oron multiple dice as part of the memory device 700. The cells in thearray 710 can be single level cell (SLC) or multilevel cell (MLC) cells,or combinations thereof. The array 710 can include the array 102 ofcells shown in FIG. 1 and the arrays 302, 304, 306 and 308 of cellsshown in FIGS. 3 and 4 according to various embodiments of theinvention.

An address circuit 712 can latch the address signals A0-Ax received onthe address signal lines 707. The address signals A0-Ax can be decodedby a row decoder 716 and a column decoder 718 to access data stored inthe array 710. The memory device 700 can read data in the array 710 bysensing voltage or current changes in cells in the array 710 using sensedevices in a sense/cache circuit 722. The row decoder 716 can includethe decoder circuit 200 shown in FIG. 2 according to various embodimentsof the invention. The sense/cache circuit 722 can include thesense/cache circuit 104 shown in FIG. 1 and the sense/cache circuit 310shown in FIGS. 3 and 4 according to various embodiments of theinvention.

A data input and output (I/O) circuit 726 implements bi-directional datacommunication over external (e.g., data I/O) nodes 728 coupled to thedata bus 708. The I/O circuit 726 includes N driver and receivercircuits 740 according to various embodiments of the invention. Thememory device 700 includes a controller that is configured to supportoperations of the memory device 700, such as writing data to and/orerasing data from the array 710. The controller can comprise, forexample, control circuitry 742 (e.g., configured to implement a statemachine) on a same or different die than that which includes the array710 and/or any or all of the other components of the memory device 700.The controller can comprise the control circuitry 742, firmware,software or combinations of any or all of the foregoing. Data can betransferred between the sense/cache circuit 722 and the I/O circuit 726over N signal lines 746. A memory request can be received in the controlsignals and the address signals A0-Ax and can be executed by thecontroller.

Each driver and receiver circuit 740 can include a driver circuit 750.Control signals can be provided to the driver circuits 750 (e.g.,through control logic circuit 768 that is coupled to the controlcircuitry 742). The control logic circuit 768 can provide the controlsignals over lines 770 and 772 to the driver circuits 750.

Apparatuses and methods described herein can distribute current flowacross an array of cells to reduce noise in the array during memoryoperations. This can lead to a significant performance improvement, andmore reliable operation.

Example structures and methods have been described. Although specificembodiments have been described, it will be evident that variousmodifications and changes may be made to these embodiments. Accordingly,the specification and drawings are to be regarded in an illustrativerather than a restrictive sense.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract that allows the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit theclaims. In addition, in the foregoing Detailed Description, it may beseen that various features are grouped together in a single embodimentfor the purpose of streamlining the disclosure. This method ofdisclosure is not to be interpreted as limiting the claims. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separate embodiment.

What is claimed is:
 1. A memory device comprising: an array of memorycells having a plurality of memory blocks, each memory block having aplurality of sub-blocks of memory cells; and control circuitry coupledto the array of memory cells, the control circuitry configured to accessa first sub-block of memory cells and a second sub-block of memory cellsat the same time, wherein the first and second sub-blocks of memorycells are part of a block of memory cells of a plurality of blocks ofmemory cells of a memory array wherein the first sub-block of the blockof memory cells and the second sub-block of the block of memory cellsare not in the same row or the same column of the block of memory cells.2. The memory device of claim 1, wherein the array of memory cells is anarray of dynamic random access memory cells.
 3. The memory device ofclaim 1, wherein the array of memory cells is an array of phase changememory cells.
 4. The memory device of claim 1, wherein the array ofmemory cells are organized as a NAND array of memory cells.
 5. Thememory device of claim 1, further comprising a decoder circuit coupledto the array of memory cells and configured to enable a plurality ofdecoding signal lines to provide enable signals in response to decodingsignals from the control circuitry.
 6. The memory device of claim 1,further comprising driver circuits coupled to the control circuitrythrough a control logic circuit, wherein the driver circuits areconfigured to output signals from the array of memory cells in responseto control signals from the control circuitry.
 7. The memory device ofclaim 6, further comprising a sense/cache circuit coupled between thearray of memory cells and the driver circuits.
 8. A memory devicecomprising: an array of memory cells having a plurality oftwo-dimensional arrays of memory cells, each two-dimensional array ofmemory cells having a plurality of sub-blocks; and control circuitrycoupled to the array of memory cells, the control circuitry configuredto access the plurality of sub-blocks of memory cells in a respectivetwo-dimensional array at the same time, the accessed sub-blocks beingseparated from each other by sub-blocks in the array that are not beingaccessed such that no accessed sub-block of the plurality of sub-blocksis in a same row or column as another simultaneously accessed sub-blockof the plurality of sub-blocks and wherein the accessed sub-blocks inthe array or memory cells occupy the same respective location in each ofthe two-dimensional arrays.
 9. The memory device of claim 8, wherein thecontrol circuitry is further configured to enable access lines coupledto the memory cells in the sub-blocks to receive programming voltages,read voltages, or erase voltages.
 10. The memory device of claim 8,further comprising decoder circuits and the control circuitry is furtherconfigured to provide an enable signal for each enabled sub-block inresponse to a plurality of decoding signals from the decoder circuit.11. The memory device of claim 8, wherein the array of memory cells is athree dimensional array of memory cells.
 12. The memory device of claim8, wherein each of the memory cells in the array of memory cells isdefined with reference to a first coordinate and a second coordinate ina coordinate system.
 13. The memory device of claim 12, wherein eachmemory cell in the two-dimensional arrays is located with reference toan x-coordinate and a y-coordinate in a Cartesian coordinate system. 14.The memory device of claim 8, wherein the memory cells are locatedaccording to a Polar coordinate system.
 15. A memory device comprising:an array of memory cells having a plurality of memory blocks, eachmemory block having rows and columns of sub-blocks of memory cells; andcontrol circuitry coupled to the array of memory cells, the controlcircuitry configured to receive a memory request and, in response to thememory request, access first data in a first sub-block of memory cellsof a block of memory cells, access second data in a second sub-block ofmemory cells of the block of cells at the same time that the first datais being accessed, wherein the second sub-block is in a row ofsub-blocks and a column of sub-blocks of the memory array that do notinclude the first sub-block.
 16. The memory device of claim 15, whereinthe control circuit configured to access the first data comprises thecontrol circuit configured to write the first data to memory cells ofthe first sub-block and the control circuit configured to access thesecond data comprises the control circuit configured to write the seconddata to memory cells of the second sub-block.
 17. The memory device ofclaim 15, wherein the control circuit configured to access the firstdata comprises the control circuit configured to erase the first datafrom memory cells of the first sub-block and the control circuitconfigured to access the second data comprises the control circuitconfigured to erase the second data from memory cells of the secondsub-block.
 18. The memory device of claim 15, wherein the controlcircuit configured to access the first data comprises the controlcircuit configured to read the first data from memory cells of the firstsub-block and the control circuit configured to access the second datacomprises the control circuit configured to read the second data frommemory cells of the second sub-block.
 19. A memory system comprising: anarray of memory cells having a plurality of memory blocks, each memoryblock having a plurality of sub-blocks of memory cells; and controlcircuitry coupled to the array of memory cells, the control circuitryconfigured to enable the plurality of sub-blocks of memory cells to beaccessed at the same time, each of the enabled sub-blocks being adjacentonly to sub-blocks of memory cells in the memory array that are notenabled to be accessed wherein no sub-block of the plurality of enabledsub-blocks in the memory block is in a same row or column as anothersimultaneously enabled sub-block of the plurality of enabled sub-blocksin the memory block.
 20. The memory system of claim 19, wherein thecontrol circuit is further configured to provide an enable signal foreach enabled sub-block in response to a plurality of decoding signals ina decoder circuit.